Proximity-triggered computer-assisted surgery system and method

ABSTRACT

A computer-assisted surgery system comprises a first surgical device with a tracking unit tracked during a surgical procedure and adapted to perform a first function associated to the surgical procedure. A second surgical device is adapted to perform a second function associated to the surgical procedure. A triggered unit is triggered when the first surgical device and the second surgical device reach a predetermined proximity relation. A surgical procedure processing unit tracks the first surgical device. A trigger detector detects a triggering of the triggered unit. A CAS application operates steps of a surgical procedure. A controller commands the CAS application to activate a selected step associated with the second function in the surgical procedure when the trigger detector signals a detection. An interface displays information about the selected step in the surgical procedure.

FIELD OF THE APPLICATION

The present application relates to computer-assisted surgery, and moreparticularly to surgical tools used in computer-assisted surgery andtriggering associated therewith.

BACKGROUND OF THE ART

Computer-assisted surgery has evolved over the years to use thecomputational speed of computers to guide surgeons and operating-roompersonnel in performing orthopedic procedures on the bones with highdegrees of precision and accuracy. In order to lessen the requirementsof hardware in the operating room, microelectromechanical systems (MEMS)such as gyroscopes and accelerometers are used in calculatingorientation and/or position of surgical tools and bones.

MEMS are used in addition or as an alternative to other types oftrackers, such as optical tracking systems (e.g., Navitrack™). In somecases, optical tracking systems can be replaced with MEMS, thereforeremoving bulky optical tracker devices on tools and bones. Because ofthe minute format of MEMS, it is even contemplated to performcomputer-assisted surgery without a self-standing monitor, by insteadproviding all information within the surgical field with LED indicatorsor screens on tools. It is desirable to automate computer-assistedsurgery using MEMS to accelerate surgical procedures.

SUMMARY OF THE APPLICATION

Therefore, in accordance with the present application, there is provideda computer-assisted surgery system comprising: a first surgical devicewith a tracking unit tracked during a surgical procedure and adapted toperform a first function associated to the surgical procedure; a secondsurgical device adapted to perform a second function associated to thesurgical procedure; a triggered unit triggered when the first surgicaldevice and the second surgical device reach a predetermined proximityrelation; a surgical procedure processing unit tracking at least thefirst surgical device, the surgical procedure processor comprising atrigger detector detecting a triggering of the triggered unit, acomputer-assisted surgery application operating steps of a surgicalprocedure, a controller for commanding the computer-assisted surgeryapplication to activate a selected step associated with the secondfunction in the surgical procedure when the trigger detector signals adetection, and an interface for displaying information about theselected step in the surgical procedure.

Further in accordance with the present application, there is provided amethod for progressing through steps of a surgical procedure of acomputer-assisted surgery application, comprising: tracking at least afirst surgical device adapted to perform a first function associatedwith the surgical procedure; detecting a predetermined proximityrelation between the first surgical device and a second surgical deviceadapted to perform a second function associated with the surgicalprocedure; activating a selected step of the surgical procedureassociated with the second function when the predetermined proximityrelation is detected; and displaying information related to the selectedstep.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a proximity-triggered computer-assistedsurgery system in accordance with an exemplary embodiment of the presentapplication;

FIG. 2 is a schematic view of mating surgical devices with respect to abone, as used with the computer-assisted surgery system of FIG. 1;

FIG. 3 is a schematic view of mating surgical devices with respect to abone, as used with the computer-assisted surgery system of FIG. 1;

FIG. 4A is a schematic view of the mating surgical devices of FIG. 2with a CAS monitor, prior to mating; and

FIG. 4B is a schematic view of the mating surgical devices of FIG. 2with the CAS monitor, after mating.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Referring to the drawings, and more particularly to FIGS. 2, 3, 4A and4B, there is illustrated a lower leg of a patient, with soft tissueremoved so as to expose an upper end of the tibia A, for use with aproximity-triggered computer-assisted surgery system of the exemplaryembodiment. Although the computer-assisted surgery system and associatedmethod are described and illustrated as used for tibial alterationsduring knee-replacement surgery, it is understood that theproximity-triggered computer-assisted surgery system and method of thepresent embodiment may be used in all other types of orthopedic surgery,such as total knee replacement, total hip replacement, spine surgery, orany other type of orthopedic surgery requiring surgical devices asdescribed for the exemplary embodiment.

Referring to FIG. 1, the proximity-triggered computer-assisted surgery(CAS) system is generally shown at 10. The CAS system 10 may feature aplurality of surgical devices. In the illustrated embodiment, the CASsystem 10 has a tracked surgical device 12 that is secured to a bone. Inthe exemplary embodiment of FIG. 1, the tracked surgical device 12 is aMEMS-operated reference unit that is secured to the bone so as toprovide tracking data (i.e., orientation and/or position information)related to the bone A through various calibration and referencing steps.

As shown in FIGS. 2 and 3, the tracked surgical device 12 is a tibialreference secured to an upper end of the tibia A, so as to act as atracking reference. The tibial reference 12 has a female connector 13 inorder to receive other surgical devices therein. In one embodiment,other surgical devices in mating engagement with the tracked surgicaldevice 12 will also be tracked by the geometrical relation between thetracked surgical device 12 and the other surgical device. In FIG. 2, theother surgical device is illustrated at 14A and is known as a tibialdigitizer. In FIG. 3, the other surgical device 14B is a cutting block.The tibial digitizer and the cutting block respectively have maleconnectors 15A and 15B.

In the exemplary embodiment, the tracked surgical device 12 haselectronic circuitry, as it operates MEMS to provide the tracking data.A triggered unit 16 (FIG. 1) is provided on the tracked surgical device12, for instance as part of the electronic circuitry, so as to betriggered when a mating engagement is completed between the femaleconnector 13 of the tracked surgical device 12 and the male connector 15of the other surgical device 14. The triggered unit 16 may be any one ofa plurality of units. For instance, the triggered unit 16 may be asimple switch that is provided in the female connector 13 so as to betriggered by the contact with the male connector 15. Other alternativesinclude a magnet and appropriate sensor, respectively in oppositedevices, proximity switches and sensors, a conductive element and anopen circuit in opposite devices, or any other appropriate type oftriggered unit or switch.

The proximity-triggered CAS system 10 features a proximity-triggered CASprocessing unit 20 that comprises a tracking calculator 22 in order totrack the surgical device and the surgical devices 14A/14B through theconnected relation with the surgical device 12, or independentlytherefrom of the surgical device 14A/14B have their own MEMS. Thetracking calculator 22 receives tracking signals from the MEMS of thesurgical devices and converts the data with prior calibration andreferencing information into tracking values related to the surgicaldevices 12, 14A and/or 14B, as well as related to the bone A or anyother appropriate bone that has been calibrated and referenced as well.

A surgical procedure controller 24 operates a CAS application 25 thatguides the surgeon and personnel of the operating room in following aseries of manual steps according to the CAS application to define boneaxes, tool axes, models, as well as in providing surgical stepinformation, to guide surgical operations on the bones. The CASapplication 25 follows a specific flow of steps according to theinformation entered by the operator of the CAS system 10, as well asthrough the tracking data provided by the tracking calculator 22. Theresulting information is displayed on an interface 26, typically amonitor of a self-standing station, or screen or LED indicators directlyon the surgical devices.

A trigger detector 28 is provided in the CAS processing unit 20 so as toreceive a detection signal from the triggered unit 16. Upon receivingthe detection signal, the trigger detector 28 signals the triggering tothe surgical procedure controller 24. The trigger detector 28 mayperform a confirmation step, for instance by confirming that thesurgical device 14 is sufficiently close to the surgical device 12, whenproximity sensors are used. Moreover, if the devices 12 and 14 matinglyengage, the trigger detector 28 may require a sustained detection signalto confirm the triggering. These confirmation steps may be performed bythe triggered unit 16 as well, in both case by the presence of aconditions database.

The triggering is automatic further to the positioning of the surgicaldevice 14 in proximity to or in contact with the surgical device 12.Accordingly, the surgical procedure controller 24 will alter its flow ofoperations following the receipt of a signal from the trigger detector28 to further advance the flow of steps of the surgical procedure, asobserved on the interface 26, for instance by the change of data on thescreen. Accordingly, by performing this action, one step of interfacingbetween the operator and the CAS system 10 is removed, and replaced byan intuitive step required in most standard surgical techniques for agiven type of procedure.

Referring to FIGS. 4A and 4B, there is illustrated the method ofautomatically triggering the CAS system by proximity. In FIG. 4A, thetibial reference 12 is secured to the tibia A, and is calibrated andreferenced. Accordingly, the tibia A is tracked for subsequent surgicalsteps thereon.

The interface 26 shows screen 1, in accordance with the progress that ismade in the surgical procedure. Screen 1 may therefore display trackinginformation (e.g., axes, bone models, values) pertaining to the bone Afrom the tracking of the tibial reference 12. Moreover, according to thesurgical procedure, screen 1 indicates that the next step is to connectthe tibial digitizer 14A to the tibial reference 12, by way of themating connection (e.g., FIG. 2) therebetween.

As mentioned previously, the positioning of the surgical device 14 maynot require the physical interconnection with the surgical device 12.The data on the screen 1 may pertain to the installation of the surgicaldevice 14 at a specific location on the bone A, per surgical technique,for instance at a given distance from the surgical device 12 asdetectable by proximity switches and sensors.

Referring to FIG. 4B, the tibial digitizer 14A is matingly connected tothe tibial reference 12, resulting in the trigger of the triggered unit16. Accordingly, if the triggering conditions are met (e.g., timelapsed, proximity, etc.), the CAS processing unit 20 automaticallychanges the data on the interface 26, as indicated by screen 2 in FIG.4B. The change of data may be the automatic change of mode in theprocedure flow to start gathering data associated with the tibialdigitizer 14A (e.g., the registration of a tibial axis), going from acommanding mode to a data-collecting mode. The change of data may alsobe an indication that the devices 12 and 14 are adequately connected toone another, thereby prompting the operator of the CAS system 10 toperform another step.

The aforementioned steps are part of a complete set of steps, some beingmandatory or optional or prerequisites as defined in the surgicaltechnique, operated by the CAS processing unit 20 in accordance with theCAS application 25. The aforementioned steps may be repeated during thesurgical procedure. For instance, when installing the cutting block 14B(FIG. 3), the automatic trigger may also cause a change in the surgicalprocedure flow.

The invention claimed is:
 1. A computer-assisted surgery systemcomprising: a first surgical device with a tracking unit tracked duringa surgical procedure and adapted to perform a first function associatedto the surgical procedure; a second surgical device adapted to perform asecond function associated to the surgical procedure; a triggered unittriggered when the first surgical device and the second surgical devicereach a predetermined proximity relation; a surgical procedureprocessing unit tracking at least the first surgical device, thesurgical procedure processor comprising: a trigger detector detecting atriggering of the triggered unit; a computer-assisted surgeryapplication operating steps of a surgical procedure; a controller forcommanding the computer-assisted surgery application to activate aselected step associated with the second function in the surgicalprocedure when the trigger detector signals a detection; and aninterface for displaying information about the selected step in thesurgical procedure.
 2. The computer-assisted surgery system according toclaim 1, wherein one of the surgical devices has a female connector,another of the surgical devices has a male connector, whereby thesurgical devices interconnect in a mating engagement of the male andfemale connectors.
 3. The computer-assisted surgery system according toclaim 2, wherein the triggered unit is a switch and the predeterminedproximity relation is the mating engagement, whereby the switch istriggered by the mating engagement of the male and the female connector.4. The computer-assisted surgery system according to claim 1, whereinthe first surgical device is a reference tool mounted to the bone fortracking of the bone.
 5. The computer-assisted surgery system accordingto claim 4, wherein the second surgical device is a digitizing toolreleasably connected to the reference tool for determining an axis ofthe bone.
 6. The computer-assisted surgery system according to claim 1,further comprising a conditions database in one of the triggered unitand the trigger detector to confirm that the predetermined proximityrelation is in accordance with conditions of the conditions database. 7.The computer-assisted surgery system according to claim 1, wherein theselected step is a change of mode, and the interface automaticallychanges mode when the trigger detector signals a detection.
 8. Thecomputer-assisted surgery system according to claim 1, wherein thesecond surgical device has a tracking unit for being tracked during thesurgical procedure.
 9. The computer-assisted surgery system according toclaim 1, wherein the tracking unit comprises a micro-electromechanicalsystem.